CMMI Basics

The CMM is composed of five maturity levels. With the exception of Level 1, each maturity level is composed of several key process areas. Each key process area is organized into five sections called common features. The common features specify the key practices that, when collectively addressed, accomplish the goals of the key process area. The components of the CMM include:

Maturity levels
A maturity level is a well-defined evolutionary plateau toward achieving a mature software process.The five maturity levels provide the top-level structure of the CMM.
Process capability
Software process capability describes the range of expected results that can be achieved by following a software process. The software process capability of an organization provides one means of predicting the most likely outcomes to be expected from the next software project the organization undertakes.

Key process areas
Each maturity level is composed of key process areas. Each key process area identifies a cluster of related activities that, when performed collectively, achieve a set of goals considered important for establishing process capability at that maturity level. The key process areas have been defined to reside at a single maturity level. For example, one of the key process areas for Level 2 is Software Project Planning.

Goals
The goals summarize the key practices of a key process area and can be used to determine whether an organization or project has effectively implemented the key process area. The goals signify the scope, boundaries, and intent of each key process area.

An example of a goal from the Software Project Planning key process area is "Software estimates are documented for use in planning and tracking the software project."

Common features
The key practices are divided among five Common Features sections: Commitment to Perform, Ability to Perform, Activities Performed, Measurement and Analysis, and Verifying Implementation. The common features are attributes that indicate whether the implementation and institutionalization of a key process area is effective, repeatable, and lasting.

The Activities Performed common feature describes implementation activities. The other four common features describe the institutionalization factors, which make a process part of the organizational culture.

Key practices
Each key process area is described in terms of key practices that, when implemented, help to satisfy the goals of that key process area. The key practices describe the infrastructure and activities that contribute most to the effective implementation and institutionalization of the key process area.

For example, one of the practices from the Software Project Planning key process area is "The project's software development plan is developed according to a documented procedure."